It is not enough for a wise man to study nature and truth; he should dare state truth for the benefit of the few who are willing and able to think. As for the rest, who are voluntarily slaves of prejudice, they can no more attain truth, than frogs can fly.
I reduce to two the systems of philosophy which deal with man's soul. The first and older system is materialism; the second is spiritualism.
In truth, to ask whether matter can think, without considering it otherwise than in itself, is like asking whether matter can tell time. It may be foreseen that we shall avoid this reef upon which Locke had the bad luck to shipwreck.
To distrust the knowledge that can be drawn from the study of animated bodies, is to regard nature and revelation as two contraries which destroy each other, and consequently to dare uphold the absurd doctrine, that God contradicts Himself in His various works and deceives us.
If there is a revelation, it can not then contradict nature.
[M]an, even though he should come from an apparently still more lowly source, would yet be the most perfect of all beings, so whatever the origin of his soul, if it is pure, noble, and lofty, it is a beautiful soul which dignifies the man endowed with it.
[E]ither everything is illusion, nature as well as revelation, or experience alone can explain faith.
Let us then take in our hands the staff of experience... To be blind and to think that one can do without this staff is the worst kind of blindness.
[T]his man who is devoured by jealousy, hatred, avarice, or ambition, can never find any rest. The most peaceful spot, the freshest and most calming drinks are alike useless to one who has not freed his heart from the torment of passion.
The soul and the body fall asleep together. ...the soul can no longer bear the burden of thought; it is in sleep as if it were not.
Opium is too closely related to the sleep it produces... This drug intoxicates, like wine, coffee, etc., each in its own measure and according to the dose. It makes a man happy in a state which would seemingly be the tomb of feeling, as it is the image of death.
The human body is a machine which winds its own springs. It is the living image of perpetual movement. Without food, the soul pines away, goes mad, and dies exhausted. ...[H]eavy food makes a dull and heavy mind whose usual traits are laziness and indolence. ...We think we are, and in fact we are, good men, only as we are gay or brave; everything depends on the way our machine is running.
One is sometimes inclined to say that the soul is situated in the stomach, and that Van Helmont, who said that the seat of the soul was in the , made only the mistake of taking the part for the whole.
One needs only eyes to see the necessary influence of old age on reason.
The soul follows the progress of the body, as it does the progress of education.
The mind, like the body, has its contagious diseases and its scurvy. ...[W]e catch everything from those with whom we come in contact; their gestures, their accent, etc... the body of the spectator mechanically imitates, in spite of himself, all the motions of a good mimic.
[A] brilliant man is his own best company, unless he can find other company of the same sort. In the society of the unintelligent, the mind grows rusty for lack of exercise...
I should prefer an intelligent man without an education, if he were still young enough, to a man badly educated. A badly trained mind is like an actor whom the provinces have spoiled.
Thus the diverse states of the soul are always correlative with those of the body.
A mere nothing, a tiny fibre, something that could never be found by the most delicate anatomy, would have made of Erasmus and Fontenelle two idiots, and Fontenelle himself speaks of this very fact in one of his best dialogues.
Willis has noticed in addition to the softness of the brain-substance in children, puppies, and birds, that the corpora striata are obliterated and discolored in all these animals, and that the striations are as imperfectly formed as in paralytics...
[S]o many different varieties can not be the gratuitous play of nature. They prove at least the necessity for a good and vigorous physical organization, since throughout the animal kingdom the soul gains force with the body and acquires keenness, as the body gains strength.
Locke, who was certainly never suspected of credulity, found no difficulty in believing the story told by Sir William Temple in his memoirs, about a parrot which could answer rationally, and which had learned to carry on a kind of connected conversation, as we do.
Whoever owes the miracles that he works to his own genius surpasses... the man who owes his to chance. He who has discovered the art of adorning the most beautiful of the kingdoms [of nature], and of giving it perfections that it did not have, should be rated above an idle creator of frivolous systems, or a painstaking author of sterile discoveries.
Let us not limit the resources of nature; they are infinite, especially when reinforced by great art.
What was man before the invention of words and the knowledge of language? An animal of his own species with much less instinct than the others. ...the same, old as young, child at all ages, he lisped out his sensations and his needs, as a dog ...asks for something to eat, or for a walk.
Words, languages, laws, sciences, and the fine arts have come, and by them finally the rough diamond of our mind has been polished. Man has been trained in the same way as animals. He has become an author, as they became beasts of burden.
A geometrician has learned to perform the most difficult demonstrations and calculations, as a monkey has learned to take his little hat off and on... All has been accomplished through signs, every species has learned what it could understand, and in this way men have acquired symbolic knowledge...
But who was the first to speak? Who was the first teacher of the human race? ...[T]he names of these first splendid geniuses have been lost in the night of time. But art is the child of nature, so nature must have long preceded it.
As a violin string or a harpsichord key vibrates and gives forth sound, so the cerebral fibres, struck by waves of sound, are stimulated to render or repeat the words that strike them.
[T]he sciences that are expressed by numbers or by other small signs, are easily learned; and... this facility rather than its demonstrability is what has made the fortune of algebra.
[I]t is comparatively rare to imagine a thing without the name or sign that is attached to it.
[E]verything is the work of imagination, and that all the faculties of the soul can be correctly reduced to pure imagination in which they all consist. Thus judgment, reason, and memory are not absolute parts of the soul, but merely modifications of this kind of medullary screen upon which images of the objects painted in the eye are projected as by a .
[W]hy should we divide the sensitive principle which thinks in man? Is not this a clear inconsistency in the partisans of the simplicity of the mind? For a thing that is divided can no longer without absurdity be regarded as indivisible. See to what one is brought by the abuse of language and by those fine words (spirituality, immateriality, etc.) used haphazard and not understood even by the most brilliant.
[I]magination is the soul, since it plays all the roles of the soul.
The more the imagination or the poorest talent is exercised, the more it gains in embonpoint... and the larger it grows. It becomes sensitive, robust, broad, and capable of thinking. The best of organisms has need of this exercise.
Man's preeminent advantage is his organism. ...Only through nature do we have any good qualities; to her we owe all that we are.
Whatever the virtue may be, from whatever source it may come, it is worthy of esteem... Mind, beauty, wealth, nobility, although the children of chance, all have their own value, as skill, learning and virtue have theirs.
According to the principles which we have laid down, and which we consider true; he who has the most imagination should be regarded as having the most intelligence or genius, for all these words are synonymous; and again, only by a shameful abuse [of terms] do we think that we are saying different things, when we are merely using different words, different sounds, to which no idea or real distinction is attached.
[T]he finest, greatest, or strongest imagination is... the most suited to the sciences as well as to the arts.
If one is known as having little judgment and much imagination, this means that the imagination has been left too much alone, has... occupied most of the time in looking at itself in the mirror of its sensations... more impressed by images than by their truth or their likeness.
[I]f attention, that key or mother of the sciences, does not do its part, imagination can do little more than run over and skim its objects.
See that bird on the bough: it seems always ready to fly away. Imagination is like the bird... [T]he soul pursues it, often in vain: it must expect to regret the loss of that which it has not quickly enough seized and fixed. Thus, imagination, the true image of time, is being ceaselessly destroyed and renewed.
[W]hat is there absurd in thinking that beings, almost as perfect machines as our selves, are, like us, made to understand and to feel nature? ...Man is not moulded from a costlier clay; nature has used but one dough, and has merely varied the leaven.
[T]here are a thousand hereditary vices and virtues which are transmitted from parents to children...
[T]here is so much pleasure in doing good, in recognizing and appreciating what one receives, so much satisfaction in practising virtue, in being gentle, humane, kind, charitable, compassionate and generous (for this one word includes all the virtues), that I consider as sufficiently punished any one who is unfortunate enough not to have been born virtuous.
Nature has created us solely to be happy—yes, all of us from the crawling worm to the eagle lost in the clouds.
I do not mean to call in question the existence of a supreme being; on the contrary it seems to me that the greatest degree of probability is in favor of this belief. But since the existence of this being goes no further than that of any other toward proving the need of worship, it is a theoretic truth with very little practical value.
[S]ince... religion does not imply exact honesty, we are authorized by the same reasons to think that atheism does not exclude it.
[W]ho can be sure that the reason for man's existence is not simply the fact that he exists? Perhaps... simply that he must live and die, like the mushrooms which appear from day to day, or like those flowers which border the ditches and cover the walls.
Let us not lose ourselves in the infinite, for we are not made to have the least idea thereof, and are absolutely unable to get back to the origin of things.
[I]t does not matter for our peace of mind, whether matter be eternal or have been created, whether there be or be not a God. How foolish to torment ourselves so much about things which we can not know, and which would not make us any happier even were we to gain knowledge about them!
[T]o destroy chance is not to prove the existence of a supreme being, since there may be some other thing which is neither chance nor God—I mean, nature.
[S]ince all the faculties of the soul depend to such a degree on the proper organization of the brain and of the whole body, that apparently they are but this organization itself, the soul is clearly an enlightened machine.
The soul is therefore but an empty word, of which no one has any idea, and which an enlightened man should use only to signify the part in us that thinks.
If now any one ask me where is this innate force in our bodies... it... resides in what the ancients called the parenchyma... in the very substance of the organs not including the veins, that arteries, the nerves, in a word, it resides in the organization of the whole body... consequently each organ contains within itself forces more or less active according to the need of them.
I wish to speak of this impetuous principle that Hippocrates calls ἐνορμὤν (soul). This principle exists and has its seat in the brain at the origin of the nerves, by which it exercises its control over all the rest of the body. By this fact is explained all that can be explained, even to the surprising effects of maladies of the imagination.
Without the precepts of hygiene, Epictetus, Socrates, Plato, and the rest preach in vain: all ethics is fruitless for one who lacks his share of temperance; it is the source of all virtues, as intemperance is the source of all vices.
[T]he soul is but a principle of motion or a material and sensible part of the brain, which can be regarded, without fear of error, as the mainspring of the whole machine, having, a visible influence on all the parts.
Stahl... has wished to persuade us that the soul is the sole cause of all our movements. But this is to speak as a fanatic and not as a philosopher.
One need only read the "Institutions of Medicine" by Boerhaave to see what laborious and enticing systems this great man was obliged to invent, by the labor of his mighty genius, through failure to admit that there is so wonderful a force in all bodies.
Willis and Perrault, minds of a more feeble stamp, but careful observers of nature seem to have preferred to suppose a soul generally extended over the whole body, instead of the principle which we are describing.
The nature of motion is as unknown to us as that of matter. I am... quite as content not to know how inert and simple matter becomes active and highly organized, as not to be able to look at the sun without red glasses...
It appears that there is but one [type of organization] in the universe, and that man is the most perfect [example]. ...He is to the ape, and to the most intelligent animals, as the planetary pendulum of Huyghens is to a watch of Julien Leroy.
[O]f two physicians, the better one and the one who deserves more confidence is always, in my opinion, the one who is more versed in the physique or mechanism of the human body, and who, leaving aside the soul and all the anxieties which this chimera gives to fools and to ignorant men, is seriously occupied only in pure naturalism.
I believe that thought is so little incompatible with organized matter, that it seems to be one of its properties on a par with electricity, the faculty of motion, impenetrability, extentension, etc.
We are veritable moles in the field of nature; we achieve little more than the mole's journey and it is our pride which prescribes limits to the limitless.
[W]e disdain, ungrateful wretches that we are, this common mother of all kingdoms... We imagine, or rather we infer, a cause superior to that to which we owe all, and which truly has wrought all things in an inconceivable fashion.
[M]atter contains nothing base, except to the vulgar eyes which do not recognize her in her most splendid works... Her power shines forth equally in creating the lowliest insect and in creating the most highly developed man; the animal kingdom costs her no more than the vegetable, and the most splendid genius no more than a blade of wheat.
Let us observe the ape, the beaver, the elephant, etc., in their operations. If it is clear that these activities can not be performed without intelligence, why refuse intelligence to these animals?
[W]ho does not see that the soul of an animal must be either mortal or immortal, whichever ours [is]... and that thus [in admitting that animals have souls], you fall into in the effort to avoid ?
Let us not say that every machine or every animal perishes altogether or assumes another form after death, for we know absolutely nothing about the subject.
[T]o assert that an immortal machine is a chimera or a logical fiction, is to reason as absurdly as caterpillars would reason if, seeing the cast-off skins of their fellow-caterpillars, they should bitterly deplore the fate of their species, which to them would seem to come to nothing.
What more do we know of our destiny than of our origin? Let us then submit to an invincible ignorance on which our happiness depends.
Full of humanity, this man will love human character even in his enemies. He will pity the wicked without hating them... [as] mis-made men. ...[T]he materialist, convinced, in spite of the protests of his vanity, that he is but a machine or an animal, will not maltreat his kind... he will not wish to do to others what he would not want them to do to him.
Such is my system, or rather the truth, unless I am much deceived. It is short and simple. Dispute it now who will.